Departments of 1Biochemistry, 2Medicine, and 3Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia; 4Departments of Pathology, Neurosurgery and Urology, Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, College of Physicians and Surgeons, New York, New York; 5Division of Human Gene Therapy, Departments of Medicine, Pathology and Surgery, and the Gene Therapy Center, University of Alabama at Birmingham, Birmingham, Birmingham, Alabama; and 6Department of Radiation Oncology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania